if exists(select * from sys.databases where name='Students')
drop database Students

create database Students
go

use Students
go

create table StuInfo
(
	StuID int primary key identity(1,1) not null,
	StuNum varchar(10) not null,
	StuName nvarchar(10) not null,
	StuGender char(2) check(StuGender='男' and StuGender= '女') default('男') not null,
	StuPhone bigint not null
)